For the purpose of this disclosure, the term “spool” generally refers to a body upon which line is wrapped. A “spool” is intended to be synonymous with the terms drum, reel, spindle, or any other body capable of accomplishing the intended purpose. Further, the term “line” is intended to be synonymous with rope, cable, strap, cord, tube, hose, pipe, wire, or any other material that is capable of being wrapped upon a “spool”.
Generally speaking, spools are commonly used to contain lengths of line. Line is wound upon a spool in successive layers by revolving the spool about an axis or axle whose plane is generally normal to the plane of the line that is being wound upon the spool.
Absent a mechanism to distribute the line evenly along the axial length of a spool as it is being would upon it, it is commonplace for line to bunch or mass, which can lead to mounds of line forming in some areas along the axial length of the spool, and valleys created in other areas along the axial length of the spool where fewer wraps of line have been amassed.
In order to prevent these mounds and valleys from occurring, it is common practice to provide a mechanism to evenly distribute the line along the axial length of the spool. This mechanism, often referred to as a “level-wind” device, is used to maximize the amount of line a particular spool can contain, to avoid tangles of the line, to ensure that the line is capable of an orderly distribution, etc.
For the purpose of this disclosure, a “level-wind” generally refers to a mechanism intended to provide a means to evenly distribute the line upon the spool upon which it is being wound. The term “level-wind” is intended to be synonymous with line-guide, spooler, guide, or any other device capable of accomplishing the intended purpose. Furthermore, the term “level-wind” encompasses any mechanism capable of traversing the axial length of a spool, whether the axial length is traversed along a straight line, an arc, or by any other shaped path.
One limitation of existing level-wind mechanisms is that they require the line that is being wound upon the spool to be threaded through an enclosed guide, or a line-guide with sufficient line enclosure so that the line is incapable of accidentally escaping the line-guide device. This is problematic because it requires a manual, cumbersome, time consuming, and often-expensive sequence in order to thread the line through such a guide. Further, such an enclosure can also create undesired points of friction between itself and the line that is being wound upon the spool, which can result in degradation of the line.
Still further, the enclosed design of all existing level-wind guide mechanisms mandate that the spool must revolve in a direction counter to that of line-retrieval in order for the line to by paid out (dispensed or extracted) from the spool. Thus, when the line is to be paid out from the spool—by unwinding the spool in the opposite direction to that of line retrieval, the line must pass through the level-wind guide. This is problematic because significant friction between the line and the level-wind mechanism results if the line-guide is not also moved axially along the length of the spool in exactly the same axial rate that the line is being unwound from of the spool. As is well known in the art, level-wind mechanisms include a drive mechanism (or motive force) that provides controlled translational movement along a line parallel to the axis of the spool. Therefore, it is a condition precedent to existing level-wind devices that this drive mechanism also functions in reverse as the line is being dispensed from this spool. Thus, powering the drive mechanism in reverse equates to the entire drive mechanism suffering a tremendous efficiency loss as it seeks to maintain harmony with the axial rate with which the line is being dispensed from the spool.
Designers sometimes seek to minimize this power efficiency loss by disengaging the drive mechanism as the line is being dispensed, and thus positioning the level-wind line guide in a stationary manner as the spool revolves counter to the direction of line retrieve in order to dispense the line. However, while solving the power efficiency loss problem, another significant problem is created. Because the level-wind mechanism moved axially along the entire length of the spool in order to distribute the line in a smooth, uniform manner, the line will oscillate from one end of the spool to the other as it is being dispensed from the spool. But, because the line guide is disengaged from its drive mechanism, it is forced to remain stationary as line is being dispensed from the spool. The axially oscillatory fashion of the line being dispensed from one end of the spool and then the other, through a fixed position line guide leads to excessive points of friction and wear on the line (leading to accelerated failure of the line), diminishes the efficiency with which the line is capable of being dispensed, and can lead to significant overruns or tangles of the line.
To overcome this newly created problem, designers took an extra step of enabling the level-wind guides—in addition to the level-wind mechanism—to also be disengaged from their motive force. This enables the level-wind guides to be shifted from a first position of line retrieval to a second position where the level-wind guides are located at opposite axial ends of the spool. Because the line guides are now located in a position so as not to interfere with the line as it is being disseminated from the spool this feature did allow for a more efficient line dissemination. Obviously, though, this feature significantly increased the complexity of level-wind mechanisms as it perpetuated the requirement that the line guides be releasably engaged/disengaged from their motive force, manually shifted parallel to the axis of the spool to the second position, releasably locked and unlocked from the second position, returnable to the first position and finally re-engaged to their motive force. Level-wind mechanism in general sometimes operate under significant forces which exacerbates mechanical failure, but even at modest forces and stresses, the reliable engagement and disengagement mechanisms for the various locking devices of the prior art have proven to be challenging at best.
A number of patents describe various level wind mechanisms, including U.S. Pat. No. 3,941,324 (Green), U.S. Pat. No. 4,106,714 (Janzen), U.S. Pat. No. 4,223,854 (Karlsson), U.S. Pat. No. 4,226,384 (Karlsson), U.S. Pat. No. 4,271,686 (Memminger), U.S. Pat. No. 4,493,463 (Rivinius), U.S. Pat. No. 4,538,937 (Lynch), U.S. Pat. No. 4,541,584 (Rivinius), U.S. Pat. No. 4,583,699 (Karlsson), U.S. Pat. No. 4,588,139 (Lines), U.S. Pat. No. 4,715,253 (Falgout, et al.), U.S. Pat. No. 4,747,560 (Karlsson), U.S. Pat. No. 5,427,327 (Anderson), U.S. Pat. No. 5,601,244 (Kawabe), U.S. Pat. No. 5,833,155 (Murayama), 5,934,586 (Kang, et al.), U.S. Pat. No. 6,089,489 (Cruickshank), U.S. Pat. No. 6,435,447 (Coats), U.S. Pat. No. 6,561,448 (Barker), and U.S. Pat. No. 6,572,041 (Morise, et al.) and herein are incorporated by reference. Moreover, all patents, patent applications, provisional applications, and publications referred to or cited herein, or from which a claim for benefit of priority has been made, are incorporated herein by reference in their entirety to the extent they are not inconsistent with the explicit teachings of this specification.